BACKGROUND: Hyperthermia (HT), while a cancer treatment approach, isn't always effective alone. Therefore, identifying hyperthermia enhancers is crucial. We demonstrated that Mito-TEMPO ([2-[(1-Hydroxy-2,2,6,6-tetramethylpiperidin-4-yl) amino]-2-oxoethyl]-triphenylphosphanium, MT) acts as a potent thermosensitizer, promoting cell death in human cervical cancer (HeLa) cells. METHODS: Cells were pretreated with 0.4 mM MT for 5 minutes, followed by exposure to hyperthermia (42 °C for 60 minutes). The impacts of MT/HT on cell viability, proliferation, apoptosis, endoplasmic reticulum (ER) stress, apoptosis-related proteins and autophagy, autophagy-related proteins expression were measured. The relationships between autophagy and apoptosis were further investigated using the specific autophagy inhibitor chloroquine (CQ) and the autophagy inducer rapamycin (Rapa). RESULTS: The combined treatment reduced the mitochondrial membrane potential (MMP) and increased ROS production. It also upregulated the pro-apoptotic protein Bax and downregulated anti-apoptotic proteins such as Bcl-2 and MCL-1. As a result, Caspase-3 was activated. Additionally, the combined treatment upregulated the expression of p-PERK/PERK, ATF-4, CHOP proteins. Moreover, the combined treatment also increased the expression of LC3 II and p62, decreased expression of LAMP 1 and Cathepsin D and increased lysosomal pH, indicating coordinated changes in autophagy regulation. Notably, intensification of apoptosis induced by the combined treatment was observed with CQ, whereas attenuation was seen with Rapa. CONCLUSIONS MT effectively enhanced HT-induced apoptosis in HeLa cells. Elevated ER stress and interruption of autophagy flux are the possible underlying molecular mechanisms for this phenomenon. These findings suggested MT can act as a potential thermosensitizer, highlighting its versatility in cancer treatment strategies.
Humans ; Apoptosis/drug effects* ; Autophagy/drug effects* ; HeLa Cells ; Uterine Cervical Neoplasms/therapy* ; Female ; Hyperthermia, Induced ; Spin Labels ; Endoplasmic Reticulum Stress/drug effects* ; Cyclic N-Oxides/pharmacology* ; Cell Survival/drug effects*

A case of 65-year-old man of aorto-caval fistula induced by ruptured abdominal aortic aneurysm is reported. The symptoms were hematuria and chest pain, and an emergent operation was performed. In the operation, Fogarty's balloon occlusion catheter was used to reduce bleeding from inferior vena cava, and to prevent pulmonary embolism. The fistula was 3cm in size, and abdominal aorta was replaced with a low porosity polyester Y-graft. The symptoms of pulmonary congestion and hematuria were improved after operation. The balloon occlusion catheter was effective for reducing bleeding from IVC, and prevention from pulmonary embolism after operation.